This invention relates to carbon fiber reinforced tantalum carbide composites, and is particularly concerned with procedure for producing omni-directional carbon or graphite fiber-tantalum carbide composites and which may also include carbon in the tantalum carbide matrix, employing a tantalum carbide precursor for infiltrating an omni-directional carbon or graphite yarn composite, and additional operational steps, without damaging the carbon or graphite fibers, and requiring a minimum number of infiltration cycles to substantially fill the voids of the preform.
The development of carbon-carbon composites formed of a carbon martrix containing high strength high modulus carbon fibers proceeded for many years despite the knowledge that the carbon matrix surrounding such fibers provides a poor matrix material for the composite in terms of strength, fiber bonding, particle erosion resistance, resistance to ablation, and the like.
To overcome these disadvantages various materials such as metals, oxides, metal carbides, metal borides, and other compounds have been incorporated into the carbon or graphite fiber reinforced composites. To a large degree many of these efforts have been unsuccessful due to gross damage of reinforcing fibers in compaction operations, thermodynamic incompatibility of fibers and matrices at fabrication and use temperatures, sometimes resulting in the dissolving of fibers, mismatch of the coefficients of thermal expansion and contraction between matrix and the reinforcing fibers, often resulting in fiber damage, and lack of sufficient bond between the matrix and the fiber, resulting in poor strength.
Illustrative of prior art composites are those disclosed in U.S. Pat. Nos. 3,736,159 and 3,766,000, comprised of graphite fibers dispersed in a matrix of a refractory metal compound such as tantalum carbide. The resulting composites are low thermal expansion composites.